When does a Chiller?

[Grizzly]

When does a chiller have one of its 2 circuits sitting (Switched off) at a pressure/ temperature of 8-10c higher than ambient?
;)

Oh! the other circuit is switched off as well.

Grizzly

[frank]

Have they changed your tablets Grizzly?? :D

[install monkey]

saving on leccy

[Magoo]

When the anti-frost heaters around vessel are operating.

[Grizzly]

I felt I had forgotten something Frank!


You got me on that one IM.

Magoo, I can understand your reasoning.Heat is not the answer to this one.

I am not trying to be clever, Honest. All will be revealed!
Grizzly

[Brian_UK]

When it's on a system defrost.

[Tayters]

Non-condensibles? But that's too easy I think.
Or perhaps thinking too much out the box, has this got something to do with non-return valves?

Cheers,
Andy.

[Magoo]

Hi Grizzly,
you have got thinking, is it full of water. OK come clean and enlighten all of us.

[monkey spanners]

Free cooling???

Or when the tanker has been and theres no milk in it....

Jon :D

[chillin out]

Ambient temp is @-6c

Chillin:):)

[Grizzly]

Sorry for leading you on Guys!
Only this one is the classic "Your wise in hind-sight!"

I know everyone of you would get the answer straight away if I presented you with all the facts.
Although they were not all present at the start, sound familiar?

This all involves a bog standard but old and tired 2 circuit R22 chiller on the roof of a 3 story office block.
Where on a previous maintenance visit circuit 1 was found to be leaking. So was shut down and leak checked further.

As the leak could not be identified a return visit was scheduled.

As neither myself or my colleague could find the leak that afternoon using nitrogen to approx 100psi. (All that was left in cylinder)
Having recovered what refrigerant was left in the system.
I returned armed with a fresh cylinder and instructions "Find the leak!" At which point I noted that System 1's pressure was down by say 20psi.

Anyway after removing lagging at all the usual places etc and getting nowhere. i just could not find the leak.

I notice that circuit 2 was high for the given ambient at below freezing.

2nd cylinder attached and system took up to 150-160psi.
I watched the 2 systems equalize!


Job done! The evap baffle plate gasket or gaskets are passing.


So Taters was correct. Non Condensables in the system.

Once again sorry for leading you all on, only sometimes as mentioned " It can be that simple!"
Only if you are aware of all the facts mind.
Oh! And the more you know, sometimes the harder it is to see the obvious.
Grizzly